How To Fix Mac Internet
Understanding Internet Addressing
When connecting to the Internet, you are assigned a Public IPv4 or IPv6 address, such as 95.31.131.123 or 2000:70e7:3738:f242:2620:f7e6:6721:dc57. You can verify your address at https://test-ipv6.com/. However, conveying these addresses to non-technical individuals or discussing MAC addresses like 83:08:6e:60:98:b1 can be error-prone and complex. Furthermore, this method does not provide historical data, especially for previous issues.
Navigating the World Wide Web
When accessing a website like https://bailey.io, your system first contacts a DNS server to translate the URL’s host portion (bailey) and the Top Level Domain (io) into an IP address, such as 167.81.140.88. Your computer and browser include their types in all web requests, for example:
Mozilla/5.0 (Windows; U; Win 9x 4.90; SG; rv:1.9.2.4) Gecko/20101104 Netscape/9.1.0285
The Significance of Default Gateways
Your default gateway is typically an automatically assigned address through DHCP, such as 192.168.231.87 (commonly ending in .1 or .254, depending on the scope size). This is where your computer directs all its traffic for further routing. For IPv6, a detailed guide on how-to-fix-ipv6-connectivity/ is available, and you can check on Mac or Linux with:
<br>
IPv4 Routes and the Host IPv4 Route Table (inc. VPN)
netstat -rn -f inet | egrep -i "default|0/1|128.0/1"
0/1 172.18.12.193 UGScg utun3 default 192.168.231.87 UGScg en0 128.0/1 172.18.12.193 UGSc utun3
Note: We are not just looking for the default but also for any VPN that overrides the public v4 address space.
IPv6 Routes and the Host IPv6 Route Table (inc. VPN)
netstat -rn -f inet6 | egrep -i "default|2000::/3"
If you have IPv6 active the above should return at least one route (as per below) via a known interface such as “en0 " on a Mac.
default fe80:76c:7568:f376:d226%en0 UGcg en0 default fe80::%utun0 UGcIg utun0 default fe80::%utun1 UGcIg utun1 default fe80::%utun2 UGcIg utun2 2000::/3 utun3 USc utun3
Note: We are not just looking for the default but also for any VPN that overrides the public v6 address space.
Debugging DHCP for both IPv4 and IPv6
To get a look at the low level DHCP configuration (Mac/Linux):
ipconfig getpacket en0
...
domain_name_server (ip_mult): {97.29.30.226, 59.135.114.170}
end (none):
...
So, in the above we are not getting IPv6 DNS servers from the DHCPv4 reply but…
ipconfig getv6packet en0
DHCPv6 REPLY (7) Transaction ID 0x80940b Length 76
Options[4] = {
CLIENTID (1) Length 14: DUID LLT HW 1 Time 668691856 Addr 83:08:6e:60:98:b1
DNS_SERVERS (23) Length 32: 2606:4700:4700::1111, 2001:4860:4860::8844
DOMAIN_LIST (24) Length 0: Invalid
SERVERID (2) Length 10: DUID LL HW 1 Addr f2:b5:1b:b4:0b:bd
}
Resolving Issues with Wired and Wireless Connections
When it comes to transmitting data to your router, you have the option of using a wired or wireless (Wi-Fi) medium at the physical and data layer.
Tips for Apple macOS / OSX Users
No matter which version of OSX/macOS you are currently using - whether it’s 10.14.1, 11.6.9, or 12.1.5 - there are various troubleshooting tools available. However, these manual actions and scripts do not provide a set of interconnected values over time. This is where automated remote troubleshooting becomes valuable, especially for teams that adopt remote work and Work From Anywhere (WFA) practices.
Utilizing Built-in Scripts for Assistance
On OSX/macOS, the sudo wdutil info tool provides a dump of current wireless settings to the CLI, and can also generate specific logs for troubleshooting. In addition, the sysdiagnose tool can be used to produce a wide range of logs, although much of it is only point-in-time data related to wireless, similar to wdutil.
To run sysdiagnose in the background and write logs to /var/tmp/<blah>.tar.gz, use the command sudo nohup /usr/bin/sysdiagnose -u &. If you prefer to run it interactively, use the command sudo /usr/bin/sysdiagnose, which will give a privacy warning and open Finder in the correct location. Alternatively, you can navigate to /var/tmp or use Finder with Cmd+Shift+G to locate the path, keeping in mind the file sizes of about 300MB.
Possibly Helpful Videos
P.S. Tips For Remote Network and Client Support
Digital work requires reliable connectivity. Whether for low latency or regular data streams, Wi-Fi, DNS, and network issues cause teams to lose time and productivity. Even worse is when support teams waste time trying to recreate and isolate issues! See how PanSift saves time, money, and frustration on all sides with instant remote troubleshooting 🏠🏝🛰.
